The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Yinguang Chen - One of the best experts on this subject based on the ideXlab platform.
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using sludge fermentation liquid to reduce the inhibitory effect of copper oxide nanoparticles on municipal wastewater Biological Nutrient Removal
Water Research, 2016Co-Authors: Yinguang Chen, Xiong Zheng, Rui Wan, Haining HuangAbstract:The deterioration of Biological Nutrient Removal (BNR) can occur with the release of engineering nanomaterials into wastewater treatment plants (WWTPs). Also, large amounts of waste sludge are generated in WWTPs, which can be reutilized as a useful resource. In this study, the use of sludge fermentation liquid to reduce CuO nanoparticles (NPs) toxicity to municipal wastewater BNR was reported. In the BNR system supplemented with sodium acetate, which was widely used as additional carbon source of municipal wastewater in literatures, the appearance of 2.5 mg/L CuO NPs for 5.5 h decreased the total nitrogen (TN) Removal efficiency from 81.4% to 59.0%, but the TN Removal was recovered to 78.7% after sodium acetate was replaced by sludge fermentation liquid. It was found that CuO NPs induced excessive generation of reactive nitrogen species (RNS), which led to the disorder of redox status, low levels of energy and reduction equivalents generations, and deterioration of denitrification. Further investigation revealed that cysteine in fermentation liquid played a vital Biological role in reducing nanotoxicity by facilitating the synthesis of glutathione, which reduced excessive RNS generation, increased key proteins expression, guaranteed the metabolisms of intracellular energy and substrate smoothly, and finally recovered the BNR performance.
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Biological Nutrient Removal with low nitrous oxide generation by cancelling the anaerobic phase and extending the idle phase in a sequencing batch reactor
Chemosphere, 2014Co-Authors: Yinguang Chen, Dongbo Wang, Xiong Zheng, Leiyu Feng, Hong ChenAbstract:Although wastewater Biological Nutrient Removal can be achieved by alternating the anaerobic–oxic–
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ph adjustment strategy for volatile fatty acid production from high strength wastewater for Biological Nutrient Removal
Water Science and Technology, 2014Co-Authors: Yinguang Chen, Qi ZhouAbstract:Volatile fatty acid (VFA) production from three types of high-strength organic wastewater (cassava thin stillage, starch wastewater and yellow-wine processing wastewater) were compared. The results showed that cassava thin stillage was the most suitable substrate, based on its high specific VFA production (0.68 g chemical oxygen demand (COD)/g initial soluble chemical oxygen demand (SCOD)) and yield (0.72 g COD/g SCOD) as well as low Nutrient content in the substrate and fermented liquid. The acid fermented cassava thin stillage was evaluated and compared with sodium acetate in a sequencing batch reactor system. Total nitrogen Removal efficiency was higher with fermented cassava thin stillage than with the sodium acetate. The effects of pH and a pH-adjustment strategy on VFA production and composition were determined using cassava thin stillage. At an initial pH range of 7–11, a relatively high VFA concentration of about 9 g COD/L was obtained. The specific VFA production (g COD/g initial SCOD) increased from 0.27 to 0.47 to 0.67 at pH 8 and from 0.26 to 0.68 to 0.81 at pH 9 (initial pH, interval pH, and constant pH adjustment, respectively). The dominant VFA species changed significantly with the increasing frequency of the pH adjustment. Further studies will examine the metabolic pathways responsible for VFA composition.
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enhanced Biological Nutrient Removal in a simultaneous fermentation denitrification and phosphate Removal reactor using primary sludge as internal carbon source
Chemosphere, 2013Co-Authors: Liang Zhang, Shuying Wang, Yongzhen Peng, Yinguang Chen, Shujun Zhang, Chengcheng Wu, Yayi WangAbstract:The production of volatile fatty acids (VFAs) from primary sludge and the subsequent application to improve Biological Nutrient Removal has drawn much attention. In this study, a novel approach of using primary sludge as an additional carbon source was conducted in batch tests. The nitritation effluent was directly injected into the sludge fermentation reactor to achieve nitrogen Removal. Complete denitrification could be realized in the combined reactor. Moreover, injecting nitrite not only promoted the sludge stabilization process, but also reduced the release of phosphate and ammonium during sludge stabilization. The novel process was further evaluated in a continuous system by treating sludge dewatering liquors. Under optimum conditions, 85% Removal of ammonium and 75% of total nitrogen could be obtained using primary sludge, resulting in the suitable effluent for recycling into the inlet of the wastewater treatment plant.
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minimizing nitrous oxide in Biological Nutrient Removal from municipal wastewater by controlling copper ion concentrations
Applied Microbiology and Biotechnology, 2013Co-Authors: Yinguang Chen, Yongzhen Peng, Hong Chen, Xiaoyu Zhu, Shuying WangAbstract:In this study, nitrous oxide (N2O) production during Biological Nutrient Removal (BNR) from municipal wastewater was reported to be remarkably reduced by controlling copper ion (Cu2+) concentration. Firstly, it was observed that the addition of Cu2+ (10–100 μg/L) reduced N2O generation by 54.5–73.2 % and improved total nitrogen Removal when synthetic wastewater was treated in an anaerobic–aerobic (with low dissolved oxygen) BNR process. Then, the roles of Cu2+ were investigated. The activities of nitrite and nitrous oxide reductases were increased by Cu2+ addition, which accelerated the bio-reductions of both nitrite to nitric oxide (NO 2 − → NO) and nitrous oxide to nitrogen gas (N2O → N2). The quantitative real-time polymerase chain reaction assay indicated that Cu2+ addition increased the number of N2O reducing denitrifiers. Further investigation showed that more polyhydoxyalkanoates were utilized in the Cu2+-added system for denitrification. Finally, the feasibility of reducing N2O generation by controlling Cu2+ was examined in two other BNR processes treating real municipal wastewater. As the Cu2+ in municipal wastewater is usually below 10 μg/L, according to this study, the supplement of influent Cu2+ to a concentration of 10–100 μg/L is beneficial to reduce N2O emission and improve nitrogen Removal when sludge concentration in the BNR system is around 3,200 mg/L.
Ignasi Rodriguezroda - One of the best experts on this subject based on the ideXlab platform.
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effects on activated sludge bacterial community exposed to sulfamethoxazole
Chemosphere, 2013Co-Authors: Neus Collado, Ignasi Rodriguezroda, Gianluigi Buttiglieri, Elisabet Marti, Laura Ferrandocliment, Sara Rodriguezmozaz, Damia Barcelo, J ComasAbstract:Abstract The bacterial community shift on a lab scale Sequencing Batch Reactor (SBR) fed with synthetic wastewater and exposed to 50 μg L −1 of sulfamethoxazole (SFX) for 2 months was investigated in this study. The impact on Biological Nutrient Removal performance and SFX Removal efficiencies were also studied. Satisfactory Biological Nutrient Removal was observed as regards to COD and Nitrogen. SFX Removal efficiencies ranged between 20% and 50% throughout the experimental period, enhanced within the aerobic phases of the SBR cycle, with no evident signs of biomass acclimation. Nevertheless, denaturing gradient gel electrophoresis (DGGE) analysis showed significant variance leading to not only the fading, but also the emergence of new species in the bioreactor bacterial community after SFX dosage. According to the phylogenetic analysis, bacteria belonging to Betaproteobacteria and Gammaproteobacteria classes were the dominant species, among them, the Thiotrix spp. ( Gammaproteobacteria ) cell number increased due to its tolerance to the antibiotic. On the other hand, the classes Sphingobacteria , Actinobacteria , Chloroflexi and Chlorobi were found to be more vulnerable to the antibiotic load and disappeared. The sulphonamide resistance gene sulI was also quantified and discussed, as there are very few studies on bacterial resistance in lab-scale treatment reactors.
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Biological Nutrient Removal in an mbr treating municipal wastewater with special focus on Biological phosphorus Removal
Bioresource Technology, 2010Co-Authors: Hector Monclus, Jan Sipma, Giuliana Ferrero, Ignasi Rodriguezroda, J ComasAbstract:abstract The performance of an MBR pilot plant for Biological Nutrient Removal was evaluated during 210 days ofoperation. The set point values for the internal recycles were determined in advance with the use of anoptimisation spreadsheet based on the ASM2d model to optimise the simultaneous Removal of C, N and P.The Biological Nutrient Removal (BNR) efficiencies were high from the start of operation with COD and NRemoval efficiencies of 92 ± 6% and 89 ± 7, respectively. During the course of the experiment P Removalefficiencies increased and finally a P-Removal efficiency of 92% was achieved. The activity of poly-phos-phate accumulating organisms (PAOs) and denitrifying poly-phosphate accumulating organisms (DPAOs)increased and the specific phosphate accumulation rates after 150 days of operation amounted to13.6 mg P g 1 VSS h 1 and 5.6 mg P g 1 VSS h 1 , for PAOs and DPAOs, respectively. 2010 Elsevier Ltd. All rights reserved. 1. IntroductionMembrane bioreactor (MBR) technology usually results in highquality effluents with low concentrations of organic matter andsuspended solids (Judd and Jefferson, 2003), as well as in a nearcomplete absence of (pathogenic) bacteria (Arrojo et al., 2005).Furthermore, MBR effluent presents a superior source for waterreclamation, since prior to high-end use water reclamation a pre-treatment with ultra-filtration membranes is required to protectthe employed reversed osmosis membranes (Cote´ et al., 2004). Be-sides efficient organic matter Removal, it was demonstrated that anMBR easily obtains efficient nitrogen Removal, ascribed to the im-proved retention of nitrifiers and the prolonged sludge retentiontimes (SRT) at which MBRs generally operate, provided that an an-oxic zone for denitrification is present (Fleischer et al., 2005; Judd,2006; Kubin et al., 2002; Monclus et al., 2010). In contrast, bioreac-tor operation at high SRT is usually characterised by a reducedBiological phosphorus Removal (Metcalf, 2003) as ultimately phos-phate Removal is the result of phosphate incorporation into newcell material and its wastage from the reactor.Although, Biological phosphorus Removal requires principallydifferent operational conditions than carbon (C) and nitrogen (N)Removal, i.e. high biomass yields and short sludge retention times,its feasibility using MBR has been demonstrated (Lesjean et al.,2003). Successful Biological phosphate Removal in an MBR is as-cribed to the development of poly-phosphate accumulating organ-isms (PAOs). The growth of PAOs is favoured in an MBR due to theircompetitive advantages over non-poly-P accumulating microor-ganisms to survive starvation periods, characteristic of an MBRoperating at low F/M ratios (Yilmaz et al., 2008). Bacteria contain-ing poly-P maintain for a longer time a high activity as a conse-quence of the accumulated energy.The extended poly-phosphate storage capacity of specializedmicroorganisms used in wastewater treatment is known asenhanced Biological phosphorus Removal (EBPR). Poly-phosphate-accumulating organisms (PAOs) require anaerobic conditions inorder to assimilate organic matter, such as volatile fatty acids(VFAs) (Puig et al., 2008), with the release of phosphorus fromstored poly-phosphate. Phosphate is taken up, under aerobic con-ditions, by PAOs (Mino et al., 1998) as well as under anoxic condi-tions in the presence of nitrate by denitrifying-poly-phosphate-accumulating organisms (DPAOs) (Kishida et al., 2006; Minoet al., 1998; Wachtmeister et al., 1997). Thus, phosphate uptakeoccurs either under anoxic or aerobic conditions increasing phos-phorus Removal efficiencies. Unlike in processes employing sedi-mentation, the final separation phase in an MBR is aerated toreduce membrane fouling, which favours the overall P-Removalefficiency as no P-release is expected during final effluent produc-tion. Furthermore, due to the complete retention of suspended
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optimization of Biological Nutrient Removal in a pilot plant uct mbr treating municipal wastewater during start up
Desalination, 2010Co-Authors: Hector Monclus, Jan Sipma, Giuliana Ferrero, J Comas, Ignasi RodriguezrodaAbstract:article i nfo This study shows that an MBR pilot plant with UCT configuration is able to obtain high Nutrient Removal efficiency already during start-up. The Biological Nutrient Removal (BNR) efficiencies significantly increased towards the end of the experimental run, achieving a COD Removal efficiency exceeding 94% and N Removal efficiency in the range of 89 to 93%. P Removal efficiencies in the range of 80 to 92% have been obtained. During the experimental period (4 months) the evolution of the activity of polyphosphate-accumulating organisms, obtained from Prelease and Puptake rates, showed a small increase in the activity of polyphosphate- accumulating organisms (PAOs) and denitrifying polyphosphate-accumulating organisms (DPAOs). The specific phosphate accumulation at the end of the experimental run amounted to 8.0 mg P g �1 VSS h �1 and 3.29 mg P g �1 VSS h �1 , for the PAOs and DPAOs respectively. Moreover, the DPAOs activity increased faster than PAOs activity, i.e. from 0.36 to 0.41 of phosphate uptake rate (PUR) ratio.
Yongzhen Peng - One of the best experts on this subject based on the ideXlab platform.
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enhanced Biological Nutrient Removal in a simultaneous fermentation denitrification and phosphate Removal reactor using primary sludge as internal carbon source
Chemosphere, 2013Co-Authors: Liang Zhang, Shuying Wang, Yongzhen Peng, Yinguang Chen, Shujun Zhang, Chengcheng Wu, Yayi WangAbstract:The production of volatile fatty acids (VFAs) from primary sludge and the subsequent application to improve Biological Nutrient Removal has drawn much attention. In this study, a novel approach of using primary sludge as an additional carbon source was conducted in batch tests. The nitritation effluent was directly injected into the sludge fermentation reactor to achieve nitrogen Removal. Complete denitrification could be realized in the combined reactor. Moreover, injecting nitrite not only promoted the sludge stabilization process, but also reduced the release of phosphate and ammonium during sludge stabilization. The novel process was further evaluated in a continuous system by treating sludge dewatering liquors. Under optimum conditions, 85% Removal of ammonium and 75% of total nitrogen could be obtained using primary sludge, resulting in the suitable effluent for recycling into the inlet of the wastewater treatment plant.
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minimizing nitrous oxide in Biological Nutrient Removal from municipal wastewater by controlling copper ion concentrations
Applied Microbiology and Biotechnology, 2013Co-Authors: Yinguang Chen, Yongzhen Peng, Hong Chen, Xiaoyu Zhu, Shuying WangAbstract:In this study, nitrous oxide (N2O) production during Biological Nutrient Removal (BNR) from municipal wastewater was reported to be remarkably reduced by controlling copper ion (Cu2+) concentration. Firstly, it was observed that the addition of Cu2+ (10–100 μg/L) reduced N2O generation by 54.5–73.2 % and improved total nitrogen Removal when synthetic wastewater was treated in an anaerobic–aerobic (with low dissolved oxygen) BNR process. Then, the roles of Cu2+ were investigated. The activities of nitrite and nitrous oxide reductases were increased by Cu2+ addition, which accelerated the bio-reductions of both nitrite to nitric oxide (NO 2 − → NO) and nitrous oxide to nitrogen gas (N2O → N2). The quantitative real-time polymerase chain reaction assay indicated that Cu2+ addition increased the number of N2O reducing denitrifiers. Further investigation showed that more polyhydoxyalkanoates were utilized in the Cu2+-added system for denitrification. Finally, the feasibility of reducing N2O generation by controlling Cu2+ was examined in two other BNR processes treating real municipal wastewater. As the Cu2+ in municipal wastewater is usually below 10 μg/L, according to this study, the supplement of influent Cu2+ to a concentration of 10–100 μg/L is beneficial to reduce N2O emission and improve nitrogen Removal when sludge concentration in the BNR system is around 3,200 mg/L.
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Biological Nutrient Removal by applying modified four step feed technology to treat weak wastewater
Bioresource Technology, 2013Co-Authors: Guihua Cao, Shuying Wang, Yongzhen Peng, Zhijia MiaoAbstract:Abstract For weak municipal wastewater (COD ⩽ 200 mg L −1 , NH 4 + -N ⩽ 40 mg L −1 ) with low influent C/N, a pilot modified four step-feed process was applied for simultaneous Biological nitrogen (N) and phosphorus (P) Removal under different inflow distribution ratios. It was designed with a short hydraulic retention time of 8.7 h to raise influent load, and the optimal effluent performance of COD, NH 4 + -N, total nitrogen (TN) and total phosphorus (TP) were 33.05, 0.58, 9.26 and 0.46 mg L −1 , respectively with inflow distribution ratio of 20:35:35:10%. More than 74% of carbon sources were utilized effectively for phosphorus release and denitrification. About 16.7% of TN was removed through simultaneous nitrification and denitrification in oxic zones. Moreover, the commendable sludge settling with a sludge loading of 0.04–0.1 kg COD/kg MLSS d, attributed to the higher mixed liquor suspended solids (MLSS) and the alternating anoxic/oxic operational mode. In addition, the pre-anoxic zone designed was beneficial for both nitrate reduction and anaerobic phosphorus release.
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effect of free nitrous acid as inhibitors on nitrate reduction by a Biological Nutrient Removal sludge
Journal of Hazardous Materials, 2010Co-Authors: Qing Yang, Shuying Wang, Li Wang, Akio Takigawa, Yongzhen PengAbstract:Abstract Nitrite has been commonly thought to have a broad inhibitory effect on bacterial metabolism. Little is known about the impact of nitrite on nitrate reduction with pH considered as an important factor. This study investigates the nitrite inhibition on nitrate reduction during denitrification under various pH conditions by using a Biological Nutrient Removal (BNR) sludge. The results showed that nitrate reduction performance had a much stronger relationship with the free nitrous acid (FNA) than that of nitrite concentration, implying that FNA, rather than nitrite, is likely the real inhibitor on nitrate reduction. The nitrate reduction activity of the biomass was observed to be inhibited about 60% in the range of 0.01–0.025 mg HNO2-N/L and was totally inhibited when FNA level was greater than the threshold concentration (0.2 mg HNO2-N/L). Moreover, the recovery rate from inhibitory effect was found to be dependent much more strongly on the concentration of FNA, of which the biomass was exposed to during the inhibition period, than on the duration of the inhibition and the feeding mode of inhibitor. It was also found that nitrite reduction was significantly inhibited by FNA and the nitrite reduction rate was linear to nitrate reduction rate due to the inhibitory mechanism under which FNA may react with the enzymes involved in the denitrification process.
George Nakhla - One of the best experts on this subject based on the ideXlab platform.
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Biological Nutrient Removal from leachate using a pilot liquid solid circulating fluidized bed bioreactor lscfb
Journal of Hazardous Materials, 2010Co-Authors: Ahmed Eldyasti, George Nakhla, Nabin Chowdhury, Jesse ZhuAbstract:Abstract Biological treatment of landfill leachate is a concern due to toxicity, high ammonia, low biodegradable organic matter concentrations, and low carbon-to-nitrogen ratio. To study the reliability and commercial viability of leachate treatment using an integrated liquid–solid circulating fluidized bed bioreactor (LSCFB), a pilot-scale LSCFB was established at the Adelaide Pollution Control Plant, London, Ontario, Canada. Anoxic and aerobic columns were used to optimize carbon and Nutrient Removal capability from leachate using 600 μm lava rock with a total porosity of 61%, at empty bed contact times (EBCTs) of 0.55, 0.49, and 0.41 d. The LSCFB achieved COD, nitrogen, and phosphorus Removal efficiencies of 85%, 80%, and 70%, respectively at a low carbon-to-nitrogen ratio of 3:1 and Nutrients loading rates of 2.15 kg COD/(m 3 d), 0.70 kg N/(m 3 d), and 0.014 kg P/(m 3 d), as compared with 60–77% COD and 70–79% nitrogen Removal efficiencies achieved by upflow anaerobic sludge blanket (UASB) and moving bed bioreactor (MBBR), respectively. The LSCFB effluent characterized by ≤35 mg SBOD/L, 4 -N/L, 4 -P/L, and 37 mg VSS/L can easily meet sewer by-law requirements. Remarkably low yields of 0.13, 0.15, and 0.16 g VSS/g COD were observed at long Biological solids retention times (SRTs) of 31, 38 and 44 d.
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effect of dynamic loading on Biological Nutrient Removal in a pilot scale liquid solid circulating fluidized bed bioreactor
Journal of Environmental Engineering, 2010Co-Authors: Nabin Chowdhury, Jesse Zhu, George NakhlaAbstract:A pilot-scale liquid-solid circulating fluidized bed (LSCFB) bioreactor was employed for Biological Nutrient Removal from municipal wastewater at the Adelaide Pollution Control Plant, London, Ontario, Canada. Lava rock particles of 600 μm were used as a biomass carrier media. The system generated effluent characterized by <1.0 mg NH4 —N/L , <6.0 mg NO3 —N/L , <1.0 mg PO4 —P/L , <10 mg TN/L, and <10 mg SBOD/L at an influent flow of 5 m3 /d , without adding any chemicals for phosphorus Removal and secondary clarification for suspended solids Removal. The impact of the dynamic loading on the LSCFB effluent quality and its Nutrient Removal efficiencies were monitored by simulating wet weather condition at a maximum peaking factor of 3 for 4 h. The achievability of effluent characteristics of 1.1 mg NH4 —N/L , 4.6 mg NO3 —N/L , 37 mg COD/L, and 0.5 mg PO4 —P/L after 24 h of the dynamic loading emphasize the favorable response of the LSCFB to the dynamic loadings and the sustainability of performance without l...
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comparative studies on membrane fouling between two membrane based Biological Nutrient Removal systems
Journal of Membrane Science, 2009Co-Authors: Mingu Kim, George NakhlaAbstract:Abstract Two lab scale membrane-based Biological Nutrient Removal systems were operated using municipal wastewater at a hydraulic retention time of 6 h and a solids retention time of 10 days. Membrane fouling parameters i.e. fouling rate, extracellular polymeric substance (EPS), soluble microbial product (SMP), particle size and sludge volume index (SVI) were monitored. It appeared that both systems showed similar membrane fouling trends with close fouling rate of 4.4 × 10 −2 LMH/kPa h. Fouling rate was more influenced by SMP than bound EPS. The higher protein/carbohydrate ratio in SMP was related with higher fouling rate. SVI and floc size were closely linked to each other and SVI was affected more by the bound protein/total protein ratio than the amount of bound protein. A statistical analysis confirmed that SMP impacts membrane fouling more significantly than floc size, the bound protein/total protein ratio and bound EPS. Biofilm layer deposited on the membrane played a beneficial role in denitrification, removing as much as 1.5 mg N/L, and was primarily impacted by dissolved oxygen (DO) and transmembrane pressure (TMP) rather than chemical oxygen demand rejection and attached biomass. The amount of nitrate reduction increased at lower DO condition (less than 2 mg/L) and the denitrification increased membrane fouling.
Hong Chen - One of the best experts on this subject based on the ideXlab platform.
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Biological Nutrient Removal with low nitrous oxide generation by cancelling the anaerobic phase and extending the idle phase in a sequencing batch reactor
Chemosphere, 2014Co-Authors: Yinguang Chen, Dongbo Wang, Xiong Zheng, Leiyu Feng, Hong ChenAbstract:Although wastewater Biological Nutrient Removal can be achieved by alternating the anaerobic–oxic–
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minimizing nitrous oxide in Biological Nutrient Removal from municipal wastewater by controlling copper ion concentrations
Applied Microbiology and Biotechnology, 2013Co-Authors: Yinguang Chen, Yongzhen Peng, Hong Chen, Xiaoyu Zhu, Shuying WangAbstract:In this study, nitrous oxide (N2O) production during Biological Nutrient Removal (BNR) from municipal wastewater was reported to be remarkably reduced by controlling copper ion (Cu2+) concentration. Firstly, it was observed that the addition of Cu2+ (10–100 μg/L) reduced N2O generation by 54.5–73.2 % and improved total nitrogen Removal when synthetic wastewater was treated in an anaerobic–aerobic (with low dissolved oxygen) BNR process. Then, the roles of Cu2+ were investigated. The activities of nitrite and nitrous oxide reductases were increased by Cu2+ addition, which accelerated the bio-reductions of both nitrite to nitric oxide (NO 2 − → NO) and nitrous oxide to nitrogen gas (N2O → N2). The quantitative real-time polymerase chain reaction assay indicated that Cu2+ addition increased the number of N2O reducing denitrifiers. Further investigation showed that more polyhydoxyalkanoates were utilized in the Cu2+-added system for denitrification. Finally, the feasibility of reducing N2O generation by controlling Cu2+ was examined in two other BNR processes treating real municipal wastewater. As the Cu2+ in municipal wastewater is usually below 10 μg/L, according to this study, the supplement of influent Cu2+ to a concentration of 10–100 μg/L is beneficial to reduce N2O emission and improve nitrogen Removal when sludge concentration in the BNR system is around 3,200 mg/L.
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Pilot-scale waste activated sludge alkaline fermentation, fermentation liquid separation, and application of fermentation liquid to improve Biological Nutrient Removal.
Environmental Science & Technology, 2011Co-Authors: Xiang Li, Yinguang Chen, Hong Chen, Lanfang Hu, Lei Yu, Guowei GuAbstract:The use of sludge fermentative short-chain fatty acids (SCFA) as an additional carbon source of Biological Nutrient Removal (BNR) has drawn much attention recently as it can reuse sludge organics, reduce waste activated sludge production, and improve BNR performance. Our previous laboratory study had shown that the SCFA production was significantly enhanced by controlling sludge fermentation at pH 10 with NaOH. This paper focused on a pilot-scale study of alkaline fermentation of waste activated sludge, separation of the fermentation liquid from the alkaline fermentation system, and application of the fermentation liquid to improve municipal Biological nitrogen and phosphorus Removal. NaOH and Ca(OH)2 were used respectively to adjust the alkaline fermentation pH, and their effects on sludge fermentation and fermentation liquid separation were compared. The results showed that the use of Ca(OH)2 had almost the same effect on SCFA production improvement and sludge volatile suspended solids reduction as that...
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pilot scale waste activated sludge alkaline fermentation fermentation liquid separation and application of fermentation liquid to improve Biological Nutrient Removal
Environmental Science & Technology, 2011Co-Authors: Hong Chen, Yinguang ChenAbstract:The use of sludge fermentative short-chain fatty acids (SCFA) as an additional carbon source of Biological Nutrient Removal (BNR) has drawn much attention recently as it can reuse sludge organics, reduce waste activated sludge production, and improve BNR performance. Our previous laboratory study had shown that the SCFA production was significantly enhanced by controlling sludge fermentation at pH 10 with NaOH. This paper focused on a pilot-scale study of alkaline fermentation of waste activated sludge, separation of the fermentation liquid from the alkaline fermentation system, and application of the fermentation liquid to improve municipal Biological nitrogen and phosphorus Removal. NaOH and Ca(OH)(2) were used respectively to adjust the alkaline fermentation pH, and their effects on sludge fermentation and fermentation liquid separation were compared. The results showed that the use of Ca(OH)(2) had almost the same effect on SCFA production improvement and sludge volatile suspended solids reduction as that of NaOH, but it exhibited better sludge dewatering, lower chemical costs, and higher fermentation liquid recovery efficiency. When the fermentation liquids, adjusted with Ca(OH)(2) and NaOH respectively, were added continuously to an anaerobic-anoxic-aerobic municipal wastewater BNR system, both the nitrogen and phosphorus Removals, compared with the control, were improved to the same levels. This was attributed to the increase of not only influent COD but also denitrifying phosphorus Removal capability. It seems that the use of Ca(OH)(2) to control sludge fermentation at pH 10 for efficiently producing a carbon source for BNR is feasible.